Nanoindentation of Bi₂Se₃ Thin Films

• Published in: Micromachines (Basel) Vol. 9; no. 10; p. 518
• Main Authors: Lai, Hong-Da, Jian, Sheng-Rui, Tuyen, Le Thi Cam, Le, Phuoc Huu, Luo, Chih-Wei, Juang, Jenh-Yih
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 14.10.2018; MDPI
• Subjects: Bi2Se3 thin films; Bismuth; Crystal structure; Deformation mechanisms; Dislocations; hardness; Materials science; Mechanical properties; Molecular beam epitaxy; Nanoindentation; Nucleation; Organic chemicals; Phase transitions; pop-in; Pulsed laser deposition; Pulsed lasers; Sapphire; Substrates; Thin films; X-ray diffraction; United States > US; Vietnam; Taiwan; hardness; nanoindentation; Bi2Se3 thin films; pop-in
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi9100518

The nanomechanical properties and nanoindentation responses of bismuth selenide (Bi₂Se₃) thin films are investigated in this study. The Bi₂Se₃ thin films are deposited on -plane sapphire substrates using pulsed laser deposition. The microstructural properties of Bi₂Se₃ thin films are analyzed by means of X-ray diffraction (XRD). The XRD results indicated that Bi₂Se₃ thin films are exhibited the hexagonal crystal structure with a -axis preferred growth orientation. Nanoindentation results showed the multiple "pop-ins" displayed in the loading segments of the load-displacement curves, suggesting that the deformation mechanisms in the hexagonal-structured Bi₂Se₃ films might have been governed by the nucleation and propagation of dislocations. Further, an energetic estimation of nanoindentation-induced dislocation associated with the observed pop-in effects was made using the classical dislocation theory.